When the public health field talks about PM2.5 as the most-deadly air pollutant, the deaths are mostly cardiovascular, heart attacks, strokes, arrhythmias, not respiratory. The American Heart Association scientific statement establishes the causal link unambiguously and quantifies it.
The mechanism is partly inflammatory and partly direct. PM2.5 particles (and especially the ultrafine fraction within them) provoke systemic inflammation and oxidative stress, alter autonomic nervous-system balance toward sympathetic dominance, and, for the smallest particles, cross from alveoli into the bloodstream and reach arterial tissue directly. Brook et al. review the human and animal evidence.
Quantitatively: a 10 µg/m³ increase in long-term PM2.5 exposure raises all-cause cardiovascular mortality risk by roughly 10% (linear, no obvious threshold), and acute exposure spikes, wildfire-smoke days, peak winter inversions, produce measurable spikes in myocardial-infarction and stroke admissions in the 24–72 hours that follow.
For Terrestream users with cardiovascular history, the dashboard's "Cardiovascular risk" setting tightens PM2.5 notification thresholds, raises filtration-recommendation priority, and surfaces outdoor PM2.5 alongside the indoor reading for any decision about ventilation. The WHO 2021 PM2.5 guideline of 5 µg/m³ is, in this context, the right number to target.
This is environmental information, not medical advice. The dashboard's readings help you make decisions about the air in your space. They do not diagnose conditions, interpret symptoms, or replace conversations with your physician. If symptoms persist, worsen, or coincide with a known exposure, talk to a healthcare professional. See the AI's medical-advice scope.
